placing, finishing, curing and jointing concrete pavement finishing curing... · placing,...

Placing, finishing, curing

and jointing concrete

pavement

ASCP Forum 14 March 2016 Todd Myers Director/Owner TSM Civil Project Management

President ASCP

TOPICS

1. Placing

2. Finishing

3. Curing

4. Jointing

PLACING, FINISHING, CURING &

JOINTING CONCRETE PAVEMENTS

ASCP Forum 14 March 2016

1. PLACING – Mixing & Hauling

ASCP Forum 14 March 2016

Local premix concrete supplier (Dry mix)

Delivery in agitators

1. PLACING – Fixed Form

ASCP Forum 14 March 2016

Fixed form paving

placing options

1. PLACING – Slip form

ASCP Forum 14 March 2016

Concrete Dumped on Grade

1. PLACING – Slip form

ASCP Forum 14 March 2016

Restricted Access – Material Transfer Placer

1. PLACING – Slip form

ASCP Forum 14 March 2016

Dowels/cages – Placer Spreader

1. PLACING – Where to Place?

ASCP Forum 14 March 2016

Minimise the auger/plow work. It is a paver, not a dozer

As close as possible

to its final location

For both:- slipform

- fixed-form

to minimise handling

1. PLACING – Start of day - Caution

ASCP Forum 14 March 2016

Start Day ‘Transition Pour’ Length TBA

Direction of paving

1. PLACING – End of day - Caution

ASCP Forum 14 March 2016

Need to cut back

into good concrete

Hand vibration of

‘Transition Lot’ in timely

manner at Start & End of

day

ASCP Forum 14 March 2016

2. FINISHING

Finishing: Is the process where surface marks or small localised high spots are

corrected.

This is separate activity to compaction.

ASCP Forum 14 March 2016

2. FINISHING

Helicopter floats

not suited to

pavements

They do not give

the right type of

surface texture

AND Curing

should have

started long ago.

ASCP Forum 14 March 2016

2. FINISHING – Tools & equipment

Bull float

Hand floats Wood & Steel

Scraping Straight Edge

Edging tools are not normally used at joints or edges for highway pavements

But these may be applicable for footpaths/cycle ways!

ASCP Forum 14 March 2016

2. FINISHING – Tools & equipment

Bull float

Short, light flat

blade, hinged for even contact

‘Float’ only

limited to closing surface marks only

2. FINISHING – Tools & equipment

Hand Float

Use limited to minor

‘touch up’ only near

edges

basic rules :

1. Do not hand float if

not necessary

2. Use to the absolute

minimum required

If excessive required

need fix paving process

2. FINISHING – Tools & equipment

Scraping Straight Edge

Length & weight allow

‘scrapping and filling of

pop marks or slight high

spots

About 2m (+) long

Steel angle or hollow

section, long handle

Caution - In hands of

inexperienced may

create issues

ASCP Forum 14 March 2016

2. FINISHING – Bleeding

Use either a bull

float or hand float in

a way that works

the surface bleed

water back into the

surface!!

ASCP Forum 14 March 2016

ASCP Forum 14 March 2016

3. Finishing - Texturing

Texturing is process of producing a skid

resistance surface - Micro texture

RMS R83 Up to 80 km/h

Hessian drag (or broom)

(min 38% sand in aggregate)

Over 80 km/h (and Roundabouts)

Hessian drag (longitudinal)

+ Tyning (transverse or longitudinal)

ASCP Forum 14 March 2016

3. Finishing - Texturing

Produced by;

• Hessian Drag

• Broom finish

ASCP Forum 14 March 2016

3. Finishing – Texturing hessian

KEY points for good hessian drag texturing

Attach to work bridge or platform behind paver at right angles to paving

Double layer in contact with concrete

Minimum 0.5 m (could be =1.5m) in contact with concrete.

Avoid bunching at edges

Watch for buildup of wet or dry mortar (warm weather)

Dampen at start & Renew drag each paving day

ASCP Forum 14 March 2016

3. Finishing – Texturing broom

Suggested points for good broom finish

Light broom, not heavy ‘bass’ broom.

Use only dead weight of broom – don’t lean on it,

don’t ‘gouge’ surface

Straight slightly overlapping runs at right angles to

pavement

Clean broom after each pass – knock dags out,

barrow with water and shake mortar out

ASCP Forum 14 March 2016

3. Finishing – Tyning Hand Pours

Finished product

The tynes are long to allow

‘flat curved’ contact with

concrete

ASCP Forum 14 March 2016

4. CURING

What is curing?

CURING is a process of retaining moisture at a

reasonable temperature to keep the reaction between

cement and moisture going. In the first day or so if either; • Concrete completely dries out, or

• Concrete freezes The reaction stops but CANNOT be restarted !!!

ASCP Forum 14 March 2016

4. CURING

Curing is important for;

Strength – pavement life &

Durability - surface wear resistance

ASCP Forum 14 March 2016

4. CURING

Curing – Ideal conditions

Concrete laboratory.

This is perfect,

under water &

controlled

temperature

Not practical in field

ASCP Forum 14 March 2016

4. CURING

Two main RMS requirements for

curing membrane

a continuous unbroken film (no gaps or holes when

applied)

maintained intact for 7 days (any damage made good ) or

concrete 25 Mpa

ASCP Forum 14 March 2016

4. CURING

Effectiveness of curing compounds

Wax or

hydrocarbon OK

Acrylics -

check test

certificates

carefully !

ASCP Forum 14 March 2016

4. JOINTING

“People Breathe - Concrete Cracks”**

All we can do is control where it cracks

**Dr Manton Hall UNSW (Concrete Technology 101 – 1986)

ASCP Forum 14 March 2016

4. JOINTING

Typ Joints

Along – 4.2m

Across – 4.3m

Essentially

square slabs

ASCP Forum 14 March 2016

4. JOINTING

Typically sawing 4- 8 hours after pour, depend on; • Air temp. • Conc. Temp • Wind • Season • Sun/Shade • Etc, Etc

ASCP Forum 14 March 2016

4. JOINTING

Typical Saw cut width 6-7mm Crack will form 1-5 days Cleaning is very important No sealing > 7 days Joints must be dry Common Silicone Sealants

• Dow Corning 888 • Parchem Road Seal SL

ASCP Forum 14 March 2016

PLACING, FINISHING, CURING &

JOINTING CONCRETE PAVEMENTS

Thankyou